# FLAP

# NOTE: This page is very old. See
www.jflap.org for the most recent version of this tool.

FLAP (Formal Languages and Automata Package), a tool for
designing, and simulating several variations of finite automata,
pushdown automata, and Turing machines. Using FLAP, one can draw a
picture (transition diagram) of a nondeterministic automaton.
Once the picture is complete, the user enters an input string and then
controls a step-by-step simulation showing multiple stacks, one for
each possible configuration. Additional features of FLAP include a fast
simulation mode, and retracing part or all of a simulation. FLAP is
currently used worldwide in teaching automata theory.

FLAP was been worked on by many people: Susan H. Rodger, Dan Caugherty,
Mark LoSacco, David Harrison, and Greg Badros.

FLAP and other tools are available via anonymous
ftp to ftp.cs.duke.edu in the directory pub/rodger/tools.

###
Pictures of automata constructed using FLAP

- Finite Automata
- Pushdown Automata
- Turing Machines
- 2-tape Turing Machines

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Example of DETERMINISTIC trace of adding two unary numbers in Turing machine
above.

- Initial starting configuration

- 1 step later

- final configuration

###
Examples of a NONDETERMINISTIC trace for palindrome Pushdown automaton above.

- Initial starting configuration

- 1 step later

- 1 step later shows 2 possible configurations

- 1 step later shows 3 possible configurations

- final configuration

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